This invention relates to a method for automatically feeding winding sleeves to a roll-cutting machine of the support roll type, as well as a roll-cutting machine for implementing the method.
In roll-cutting machines of the support roller type, the winding devices are usually so-called centre winders, since the clamping heads gripping the winding sleeves for holding the ends of the cut sheets to be wound are driven in the winding direction. These known roll-cutting machines produce good winding results and have been used in the industry for many years. The production capacity of these machines is greatly limited by the amount of time and effort required to change the rolls/winding sleeves. This procedure takes from five to either minutes and requires up to four or five workers, depending on the number of stations. The average cutting and winding time amounts to approximately 12 minutes. This means that the machine is not productive 30 to 40% of the time (DE 38 00 703 A1).
In roll cutting machines with one support roll as well as in those with two support rolls, with the sheets being fed from below in to the winding station, it is known to feed the winding sleeves automatically from above the support roll(s). According to DE 38 00 703 A1, a feed beam is provided for each of the two winding stations positioned alongside the support roll(s); this feed beam extends across the entire width of the machine, which can be eight to ten meters, and is supported by swivel arms at the end faces of the machines. Each feed beam has a groove for holding the winding sleeves. If the two feed beams are swivelled toward each other and are positioned close together, the two grooves lie so close together that there is room for only one winding sleeve in each longitudinal segment of the feed beam. This makes it possible to alternately transfer the winding sleeves, which are already cut to length, from one feed beam end to the groove on one feed beam or the other an, with the aid of a slide, push the entire unit along the two grooves until it reaches the transfer positions corresponding to the winding fixtures positions. The winding sleeves are thus distributed to the two grooves belonging to each of the winding stations as soon as they are inserted into the grooves. A functionally reliable distribution is difficult in this case. In order to fit the individual winding fixtures with new winding sleeves, the feed beams must be swivelled in an arc in the direction of the support arm pairs for the winding fixtures. While they are being swivelled, the winding sleeves roll into the grooves receiving them from one initial stable position to another stable position, where they are prevented from rolling out of the groove by a swivelling stop. The stops are pivotably attached to the feed beam under a spring loading so that the stop plate positioned in the region of the support arms for the winding fixtures can avoid contact with the support arms.
This known feed device has three primary disadvantages: First, there is a danger that, when the winding sleeves roll from one stable position to the other, the swing (momentum) of the rolling winding sleeves becomes so great that the stop plates whose surfaces are rounded cannot stop this rolling movement. This danger is present primarily with winding sleeves of a relatively large diameter and/or a relatively great weight. Secondly, alignment of the winding sleeves to the clamping heads of the winding fixtures requires great effort, primarily if the winding sleeve diameter has to be changed and/or sleeves of different diameters are to be wound during a single winding cycle. Finally, it is difficult to transfer winding sleeves in different grooves to their precise transfer positions.
Some simplification of the winding sleeve feed device is proposed in DE 37 37 503 A1 for a roll-cutting machine with two support rolls. In this machine, all winding sleeves necessary for a single winding cycle are positioned in a single groove. The winding sleeves are not distributed to the sides corresponding to the two winding stations until the winding sleeves have been placed in their transfer positions corresponding to the winding fixtures. They are distributed by flipping open the groove from below and transferring the winding sleeves to alternating gripping arms which pull the winding sleeves to the correct side and place them on an inclined pane leading to the clamping position of the relevant winding sleeve. These known winding sleeve feed devices also require a stop which prevents the winding sleeve from rolling further and holds it in the precise clamping position. This known winding sleeve feed device requires a relatively large number of moving parts. It also requires a great deal of alignment work when the width of the cut sheets and/or winding sleeve diameters are changed. Finally, when changing the cut sheet widths, the gripping arms must be re-aligned independently, i.e. separately from the winding devices. A box girder extending across the entire width of the machine and having side-mounted guide rails which can be fitted with slides has to be provided for this purpose.